In the prior art, the air produced by an air compressor is usually employed for pressing the sealant within a sealant bottle into a tire during the process of tire repair. Afterwards, by means of slow forward movement of the automobile, the sealant pressed thereinto can cover an inner wall of the tire uniformly for achieving the tire repair. Accordingly, such process for tire repair is simple in operation. However, a valve plug of the tire which is connected with the sealant bottle may be blocked, or a sealant outlet at a bottle cap of the sealant bottle may not be opened smoothly under the action of air during this process. In this case, the pressure within the sealant bottle will build up increasingly and thus a danger of explosion may be caused.